Differences in the microtubule organization between normal and cml granulocytes after stimulation with chemotactic peptide

Chemotaxis of polymorphonuclear leukocytes (PMNL) from chronic myeloid leukemia (CML) patients followed in a gradient of a chemotactic peptide n-formyl-methionyl-leucyl-phenylalanine (fMLP) is consistently defective in all the phases of the disease. Chemoattractant-induced polymerization of cytoskeletal proteins (actin and tubulin) plays a major role in regulation of cell shape and cellular motility. To study the role of microtubules in defective chemotaxis, we have compared fMLP-induced alterations in organization of microtubules in PMNL from CML patients with those from normal subjects by laser confocal microscopy. Our analysis shows differences in microtubule organization between normal and CML PMNL and suggests that both nucleation of new microtubule and elongation of pre-existing microtubules are essential for PMNL chemotaxis.